JP2016535339A - Active pen with pressure sensor at tip - Google Patents

Abstract

The active position indicator is moved from its initial position in the direction of displacement by displacement of the tip depending on the force acting on the tip (3) arranged on the distal end of the tip element (10). A movable tip element (10) configured as described above and an elastic element that acts on the tip element (10) against the displacement of the tip portion, for detecting a force acting on the tip portion (3) A force sensor is provided, and the elastic element is a leaf spring (15).

Description

  The present invention relates to an active position indicator, particularly an active pen, equipped with a pressure sensor.

  Touch devices are used in a variety of applications, where detection of the presence of objects is not limited, such as touchpads, touch panels, touch screens, or projected capacitive displays. Detection of the presence of such objects. The touch device can detect a passive object in contact with the touch device and determine the position of the contact. Thus, for example, user control can be performed. It is unsuitable that the quality of contact position detection decreases with the size of the contact surface. Therefore, the quality of the position detection of the tip of the pen may be detected only by a high detection error. Thus, an active position indicator, such as an active pen, includes an electrical circuit for supporting the touch device to detect the position of the active position indicator with low error. This can be achieved, for example, by capacitive coupling or inductive coupling. When using certain types of touch devices, such as capacitive touch devices or inductive touch devices, the same sensor for detecting passive touch detects electrical signals emitted from the tip of an active position indicator May be used for There are different types of active position indicators. There are active position indicators that synchronize with a window that emits an electrical signal to detect a particular active position indicator. There are other active position indicators by continuous transmission of electrical signals, ie without any synchronization in the active position indicator with respect to the touch device. There is an active position indicator that is activated by a battery or by an energy intake device for obtaining energy from the environment. There are also active position indicators without a power supply that are actuated like a transponder to obtain the power required for actuation from the transponder signal. Patent Document 1 shows a capacitive touch device with an active position indicator that emits continuously, for example, and the capacitive touch device has the same capacitive detection sensor for detecting passive and active touches. use.

  Another problem with good detection of interactions written on touch devices is how to understand the pressure applied by the pen. Some touch devices can directly detect the applied pressure. However, in most solutions with active pens, the pen includes a pressure sensor that detects the pressure applied to the tip and sends the detected pressure back to the touch device. However, the state of the art solution for pressure sensors has several disadvantages.

  Pressure sensors require movable parts, springs and often electrical connections of the movable parts to the printed circuit board. This increases time due to pen assembly, structural complexity and robustness.

  In particular, while drawing or writing, the force applied to the active pen can change from a very small force to a very high force. This increases the difficulty of detecting the tip force applied with high accuracy.

  One problem is the normal use of spiral springs or other elastic elements with a certain stiffness. Thus, a constant change in the force applied to the tip will result in the same displacement of the tip for weak and strong forces. The tip displacement is only minimal, so the realization can detect small forces with high accuracy, but it cannot detect large forces above a certain threshold, or it has a high force range up to high applied forces. Detect with low accuracy. Both alternatives are inadequate, so the less rigid spring is dominant with respect to weak forces and the rigid second spring is dominant with respect to large forces to expand the range of forces that can be detected by the pressure sensor Thus, some solutions include two springs with different stiffnesses. However, such a solution increases the complexity, size and robustness of the pressure sensor. Furthermore, spiral springs have the problem of being difficult to assemble and requiring a large space.

  Another problem with detection accuracy is that the maximum tip displacement that can be used to detect the applied force is very small. A capacitive element having a capacitance value depending on the displacement of the tip is often used to detect the actual displacement of the tip. When the distance between the two capacitor plates changes depending on the displacement of the tip, this gives a capacitance value that depends on the reciprocal of the displacement of the tip. Therefore, a small tip displacement can be detected with very high accuracy because of a fast change in capacitance value, but a large tip displacement can quickly detect accuracy due to a gradual change in capacitance value. Go down. Alternatively, there are means for detecting tip displacement with linear behavior. However, such a linear solution means cannot achieve high accuracy with a small tip displacement. Despite the disadvantages, the capacitive solution has the advantage that it is well known and can be implemented easily.

International Patent Application Publication No. 2014/174123 Specification

  Accordingly, an object of the present invention is to provide an active position indicator with a pressure sensor that overcomes the above-mentioned problems.

  It is an object of the present invention to provide an active position indicator with a pressure sensor that reduces the time to assemble a pen, reduces structural complexity, and increases robustness.

  It is an object of the present invention to provide an active position indicator having a low-complexity pressure sensor having a highly accurate force detection range in a small force state.

  In an embodiment, these problems are achieved by the independent claims.

  In one embodiment, these tasks are accomplished by an active position indicator having the following features. The movable tip element is configured to be moved by displacement of the tip portion depending on a force acting on the tip portion. The force sensor for detecting the force acting on the tip portion includes an elastic element acting on the tip element against the displacement of the tip portion, and the elastic element is a leaf spring.

  The leaf spring is manufactured from a single spring leaf material and has the great advantage that it can be highly adapted to requirements such as shape, size and stiffness depending on the displacement of the tip. Furthermore, the leaf spring can easily come into contact with the displacement of the movable tip.

  In one embodiment, these tasks are achieved by an active position indicator with the following features. The movable tip element is configured to be moved by displacement of the tip portion depending on the force acting on the tip portion. A position signal circuit is connected to the movable tip element and is configured to generate an indicator position signal for electrical coupling with the touch device by the tip. The force sensor for detecting the force acting on the tip portion includes a capacitive element having a capacitance value depending on the displacement of the tip portion in order to generate a feedback signal for notifying the displacement of the tip portion. The capacitive element has a capacitance distance depending on the displacement of the tip and a capacitance area depending on the displacement of the tip.

  This means that the behavior of the capacitance value over the displacement of the tip can be configured with a high degree of freedom so that the force range and sensitivity requirements for particularly small forces can be achieved. Has advantages.

  In one embodiment, these tasks are achieved by an active position indicator with the following features. The movable tip element is configured to be moved by displacement of the tip portion depending on a force acting on the tip portion. A position signal circuit is connected to the movable tip element and is configured to generate an indicator position signal for electrical coupling with the touch device by the tip. A force sensor for detecting a force acting on the tip includes an elastic element that acts on the tip element against displacement of the tip. The elastic element is electrically conductive, and the position signal circuit is electrically connected to the movable tip element via the elastic element.

  This has the advantage that an element for contacting and an elastic element for acting against the force of the tip can be combined. This saves space and avoids the problem of contacting movable elements.

In one embodiment, these tasks are achieved by an active position indicator with the following features. The movable tip element is configured to be moved by displacement of the tip portion depending on the force acting on the tip portion. The force sensor for detecting the force acting on the tip has an elastic element that acts on the tip element against the displacement of the tip, and the elastic element has a nonlinear stiffness depending on the displacement of the tip. .

  Non-linear springs have the advantage that a constant change in force with a small force can result in a greater change in tip displacement compared to a constant change in force with a larger force.

  The invention is better understood and illustrated in the figures by the description of the examples given by way of example.

FIG. 3 shows a three-dimensional view of an embodiment of an active pen. FIG. 2 shows a three-dimensional view of the embodiment of FIG. 1 without an outer housing. FIG. 3 shows a three-dimensional view of an embodiment of a force sensor for an active pen. Fig. 4 shows a three-dimensional view of the force sensor of Fig. 3 with a transparent housing of the force sensor. The top view of the 2nd capacitor board of the capacitive element of the force sensor of FIG. 3 is shown. FIG. 4 shows a cross-sectional view of the capacitive element of the force sensor of FIG. 3 with a first capacitor plate and a second capacitor plate. FIG. 4 shows a three-dimensional view of the capacitive element of the force sensor of FIG. 3 with the first capacitor plate and the second capacitor plate in the initial position. FIG. 4 shows a plan view of a capacitive element of the force sensor of FIG. 3 provided with a first capacitor plate and a second capacitor plate. FIG. 4 shows a three-dimensional view of the force sensor housing of FIG. 3 with a spring. FIG. 4 shows a plan view of the housing of the force sensor of FIG. 3 with a spring. FIG. 10 shows a three-dimensional view of the spring of FIG. 9. Fig. 10 shows a first side view of the spring of Fig. 9; Fig. 10 shows a second side view of the spring of Fig. 9; FIG. 6 shows a plan view of an alternative embodiment of a spring. FIG. 13B illustrates a side view of an alternative embodiment of the spring of FIG. 13A. FIG. 13B illustrates a production stage of an alternative embodiment of the spring of FIG. 13A. 4 shows a curve showing the capacitance values of different capacitive elements with respect to the force applied to the tip 3.

  1 to 13 show an embodiment of an active pen 5. Everything disclosed by the active pens described below is applicable to all other types of active position indicators.

  The active pen 5 includes a pen housing 6, a battery 7, a printed circuit board 8, a force sensor and a tip element 10 having a tip 3.

  The pen housing 6 preferably seals the battery 7, the printed circuit board 8, and the force detection mechanism 9 of the force sensor. The pen housing 6 includes the tip element 10 such that the tip 3 is disposed outside the pen housing 6 and is connected to the internal chamber of the pen housing 6 via the rod-like body 11 of the tip element 10. It is preferable to provide the opening part. The opening of the pen housing 6 preferably guides the rod 11 of the tip element 10 only so that the tip element 10 can be moved in the displacement direction. However, it is also possible to detect forces in different directions. The pen housing 6 has a cylindrical shape, and the displacement direction is preferably parallel to the longitudinal cylindrical axis. According to the definition, the side / end of the active pen 5 with the tip 3 is named the distal side / end and the opposite side / end of the active pen 5 in the displacement direction is proximal Called side / end. In the illustrated embodiment, the pen housing 6 comprises a battery 6.1, a cylindrical part 6.1 having a printed circuit board 8 and a force detection mechanism 9, a conical part 6.2 having said opening and tip elements and a cap 6. 3 is provided. Furthermore, the tubular part 6.1 comprises a power button 6.4 configured to interact with the power switch 8.1 on the printed circuit board 8. The conical part 6.2 is attached at its proximal end to the distal end of the tubular part 6.1. The distal end of the cone 6.2 is provided with an opening for the tip element 10. The cone 6.2 preferably has a conical shape that narrows from the proximal end to the distal end. The proximal end of the cylindrical housing 6.1 is attached to a cap 6.3 that closes the pen housing 6 at the proximal end. In a preferred embodiment, the cap 6.3 should be removable for replacing the battery 7, for example by a fastener or a threading mechanism. In addition, the cap 6.3 should generate the necessary contact pressure to connect the battery terminal of the printed circuit board 8 to the power supply terminal.

  The illustrated embodiment of the active pen 5 is operated by a battery 7 as a power source. However, any other means of supplying the necessary power may alternatively be used. For example, the battery 7 can take in energy from ambient conditions, for example, light, temperature, electromagnetic waves (eg, from a touch device), electrical coupling (eg, with a touch device), pen movement, etc. It can be replaced by a mechanism.

  The printed circuit board 8 comprises all or at least most of the electronic circuit components of the active pen 5 in this embodiment. The printed circuit board 8 has a longitudinal axis parallel to the longitudinal axis of the cylindrical part 6.1 of the active pen 5 or of the pen housing 6. The size of the printed circuit board 8 corresponds in one embodiment to the inner diameter of the pen housing 6, in particular the cylindrical housing 6.1. In the illustrated embodiment, the printed circuit board 8 is held by or at the distal end of the force sensing mechanism 9 and / or the proximal end of the power terminal 8.3 of the printed circuit board 8. Hold. The housing 9 of the force detection mechanism is such that the printed circuit board 8 is additionally fixed in all radial directions via the housing 9.1 of the force detection mechanism 9 and / or via the power supply terminal 8.3. .1 and / or the power supply terminal 8.3 has a cylindrical shape corresponding to the internal shape of the hollow cylinder provided by the housing 6. However, the printed circuit board 8 may be directly fixed in the housing 6 by, for example, a rail for the printed circuit board 8. The printed circuit board 8 forms two arms 8.2 at its distal end configured to hold the housing 9.1 of the force detection mechanism 9. In order to allow the maximum distance between the two arms 8.2, the arms are on both sides of the printed circuit board 8 with a thickness that should resist the expected stress on the housing 9.1 of the force detection mechanism. Is arranged. The housing 9.1 of the force detection mechanism can be provided with two recesses 13 (shown in FIGS. 3 to 5 and FIGS. 7 to 10) to constitute the two arms 8.2 of the printed circuit board 8. The dimensions of the arm 8.2 and the recess 13 are preferably designed so that the arm 8.2 occupies the recess 13, and as a result, the housing 9.1 is in a radial direction relative to the direction of displacement of the tip 3. I can't move. The side surface of the force detection mechanism housing 9.1 (the surface generally in the radial direction with respect to the longitudinal axis of the housing 6) is in contact with the side surface of the printed circuit board 8. The distal end of the arm 8.2 may be provided with a hook in order to fix the force detection mechanism housing 9.1 in the longitudinal direction of the printed circuit board 8 and to realize a snap-fit fixing. . However, other fixations are possible.

  The printed circuit board 8 preferably includes a position signal circuit for generating and outputting a pen position signal. The pen position signal is preferably a periodic signal, such as a sine wave signal and / or a cosine wave signal, and the constant frequency is suitable for transmission and detection in a touch device. Such a position signal circuit includes, for example, an oscillator and an amplifier. The output portion of the position signal circuit is preferably connected to at least one output terminal of the printed circuit board 8. The output portion of the printed circuit board 8 is preferably conductively connected to the tip portion 3 for supplying a pen position signal generated at the tip portion 3. A signal applied to the tip 3 creates electrical coupling with the touch device. Such coupling is preferably capacitive coupling and / or inductive coupling, but may be any electromagnetic emission that can be received by the touch device. The output terminal is preferably conductively connected to a conductive elastic element holding the tip element 10 in its initial position, for example a metal spring that is conductively connected to the tip element 10. This solves the problem of bringing the movable tip element 10 into contact with the fixed printed circuit board 8.

  The printed circuit board 8 preferably includes a force detection circuit of a force sensor for detecting a force applied to the tip 3 based on an electronic feedback signal received from the force detection mechanism 9. The input portion of the force detection circuit is preferably conductively connected to at least one feedback input terminal of the circuit board 8. At least one feedback input terminal of the circuit board 8 is preferably disposed on at least one of the two arms 8.2 configured to contact the feedback terminal of the force detection mechanism 9. Accordingly, at least one recess 13 has a conductive surface, which is in conductive contact with the conductive surface of at least one arm 8.2 with at least one feedback input terminal. There are preferably two input terminals for the feedback signal of the force detection mechanism 9 in each of the two arms 8.2 of the printed circuit board 8. In the embodiment shown, the force detection mechanism 9 comprises a variable capacitive element having a capacitance value that depends on the displacement of the tip (described below). In the illustrated embodiment, the pen position signal is sent to the second capacitor plate 12 of the capacitive element and the feedback signal is sent from the first capacitor plate 14 of the capacitive element to the force detection circuit. Since the pen position signal has a fixed frequency or at least a known frequency, the complex resistance of the path from the second capacitor plate 12 to the force detection circuit depends on the capacitance value of the capacitive element. Therefore, the capacitance value of the capacitive element, which itself depends only on the displacement of the tip, can be determined by the feedback signal. The force detection circuit measures a value for the complex resistance, and this value is provided by a capacitive element that can be processed into a value related to the force, for example by means of a lookup table. An example for determining the complex resistance can be determined, for example, by rectifying the feedback signal and applying a low pass filter to the feedback signal. This gives a value for the amplification of the feedback signal giving a measurement for the complex resistance. Instead of the pen position signal, other signals applied by the capacitive element can be used to detect the capacitance value. However, other measurement methods for other electronic values depending on the capacitance value or the displacement of the tip element are also determined and / or converted into force values in the force detection circuit.

  Furthermore, the printed circuit board 8 may include a force data transfer circuit for transferring the detected force (force data) that causes the tip 3 to act on the touch device. In one embodiment, the force data transfer circuit is connected to the tip 3 for transferring force data to the touch device by electrically coupling the tip 3 with the touch device. The force data can be transferred during the period of the pen position signal and / or the force data can be modulated continuously or in a data transfer window for the pen position signal. Different modulations such as frequency, amplification or other modes of modulation may be used here. In another embodiment, the force data transfer circuit is connected to an antenna (rather than the tip 3) for transferring force data to the touch device. In other embodiments, force data may be transferred to the touch device via a wired connection.

  However, the present invention is not limited to the printed circuit board 8. Other circuit boards or other implementations of electronic circuitry may also be used to fulfill the electronic functionality of the active pen.

  The tip element 10 comprises a tip 3 at the distal end and a first capacitor plate 12 of a capacitive element at the proximal end. The first capacitor plate 12 is also part of the force detection mechanism 9 which will be described in more detail later. The tip 3 and the first capacitor plate 12 are connected by a rod-like body 11. The tip 3 is provided with a conductive material for outputting a pen position signal received from the position signal circuit. In the embodiment shown, the tip 3 comprises a conductive core 3 ′, preferably a metal core as shown in FIGS. 3 and 4, which is covered by a protective cap, The protective cap is configured to pass outgoing pen position signals and / or is configured to avoid any damage to the touch screen. In order to guide the position signal of the pen to the tip 3, the rod 11 is also preferably provided with a conductive material, preferably a metal, or made of a conductive material, preferably a metal. In an alternative embodiment, the bar 11 is made of a non-conductive material and includes a conductor for guiding the pen position signal from the position signal circuit to the tip 3. Such a conductor may be a conductive core of the rod-shaped body 11. The first capacitor plate 12 is also preferably made of a conductive material, preferably metal. However, it is also possible to make the first capacitor plate 12 from a non-conductive material with a metal coating or metal surface for at least one capacitor surface of the capacitive element of the force detection mechanism 9 described later. is there. The tip element 10 is movably supported so that the tip element 10 can be moved at least in the displacement direction. Support can be provided by the housing 6, for example by an opening in the housing 6, and / or by a force detection mechanism 9. When there is no force applied to the tip 3, the tip element 10 is arranged at the initial position. Furthermore, the tip element 10 is arranged to be moved from the initial position by the displacement of the tip portion depending on the force applied to the tip portion 3. The active pen 5 may be provided with a maximum stop element for the tip element 10 that limits the tip displacement to the maximum tip displacement. Such a maximum stopper element can be provided in the housing 6 or the force detection mechanism 9.

  The force detection mechanism 9 resists a capacitive element having a capacitance value depending on the displacement of the tip, and a force applied to the tip 3 for holding the tip element in the initial position and / or in the displacement direction. And an elastic element.

  In the embodiment shown, the capacitive element comprises a first capacitor plate 14 and a second capacitor plate 12. The first capacitor plate 14 is preferably fixed with respect to the housing 6 and / or the housing 9.1 of the force detection mechanism 9, but the second capacitor plate 12 moves depending on the displacement of the tip. Alternatively, it is also important that there is a relative movement of the first and second capacitor plates 14 and 12 relative to each other. In the illustrated embodiment, the second capacitor plate 12 is positioned at the initial position of the tip element 10 at a minimum distance relative to the first capacitor plate 14 and the first and second The first capacitor plate 14 is arranged so that the distance between the capacitor plates 14 and 12 increases linearly with the displacement of the tip. In the illustrated embodiment, the minimum distance is zero so that the first and second capacitor plates 14 and 12 are conductively connected and the initial position of the tip element 10 is easily detectable. is there. However, it is possible that the minimum distance between the capacitor plates is not equal to zero. This avoids short circuits due to increased power consumption. This can also be used to adjust the behavior of the capacitance value of the capacitive element. The reason is that this reduces the initial value of the capacitance value at the initial position of the tip 3 (if there is another capacitive part with the linear behavior described later, this means that Increase linear behavior). Between the first capacitor plate 14 and the second capacitor plate 12, an insulating material or dielectric material for realizing a non-zero initial position between the two capacitor plates 12 and 14 is disposed. This can be achieved by coating the surface 12.1 or 12.2 with an insulator or dielectric coating. In one embodiment, the first capacitor plate 14 is disposed on the distal side (near the tip 3) and the second capacitor plate 12 is disposed on the proximal side (far from the tip 3). ing. This is achieved by guiding the rod 11 through the first capacitor plate 14, preferably in the center.

  In one embodiment, the capacitive element has a capacitance value that depends on the displacement d of the tip. The capacitance value C of the capacitive element is calculated based on the capacitor area A of the capacitive element and the capacitor distance x of the capacitive element. If the capacitance component is given by two parallel planes with capacitor area A and capacitor distance x, the capacitance value is proportional to capacitor area A divided by capacitor distance x, ie A / x.

State in the first embodiment of the capacitor, the capacitor plate, the normal is parallel to the displacement direction of the distal end portion 3, the capacitor distance x ₁ is proportional or directly equal to the displacement d of the distal portion in, and a metal surface overlaps and faces on the plate surfaces a _1. This gives a capacitance value C ₁ that is directly proportional to the inverse 1 / d of the tip displacement. Since the complex resistivity Z ₁ is directly proportional to the inverse of the capacitance value, the complex resistivity is in this case linearly proportional to d. However, this has the disadvantage that a small displacement d of the tip can be detected with the same absolute error as a large displacement d of the tip. However, since it is desired to have high sensitivity due to the small displacement of the tip, therefore, for a small displacement d of the tip, the relative error becomes large and such a solution is not desired. FIG. 14 shows the capacitance values of different capacitive elements with respect to the force applied to the tip 3 (with an elastic element having a constant stiffness). Functions 18 and 20 show a capacitor according to the first embodiment with an outer diameter D ₀ and the inner diameter D ₁ capacitor surface A1 defined by a ring having a. The function 18 corresponds to a diameter relationship of D ₁ / D ₀ = 0.3, and the function 20 corresponds to a diameter relationship of D ₁ / D ₀ = 0.9. Functions 18 and 20 have steep tip displacements for small forces, but these gradients are subject to tip displacements for increasing forces so that the detection error for large forces is quite large. For always become flatter.

In the second embodiment of the capacitive element, the normal is perpendicular to the displacement direction of the tip 3 and the capacitor surface A2 is equal to or directly proportional to the displacement d of the tip. The plate has a metal surface facing the plate surface. Capacitor area A ₂ overlapping is to increase or decrease the displacement d and linear tip, the two faces of the two capacitor plates are arranged, the distance x ₂ remains constant. Thus, the capacitance value C ₂ which is directly proportional to the displacement d of the tip portion is obtained. Complex resistivity Z _2, since directly proportional to the reciprocal of the capacitance value, in this case the complex resistivity, is linearly proportional to the 1 / d. Thus, small changes with small displacement of the tip can be detected fairly accurately compared to changes with large displacement of the tip due to higher capacitance value changes. However, this method also has disadvantages. The reason for this is that the characteristic for detecting a change due to a large displacement of the tip can now only be detected with a large error due to the substantially flat behavior of the capacitance value.

A third embodiment of the capacitive element provides the first and second in order to achieve the behavior of the capacitance value over the tip displacement d, which changes faster than the large tip displacement, at a small tip displacement. Combining the advantages of both embodiments, this does not have the negative impact of the second embodiment of the capacitive element. This is achieved by a capacitive element whose capacitor area and capacitor distance both change depending on the displacement d of the tip. Such an achievement is proved by the active pen 5. Accordingly, the first capacitor plate 12 has a lateral conductive plate surface 12.2 in a state where the normal of the surface is perpendicular to the displacement of the tip portion (positioning with respect to the outside of the active pen). A conductive plate surface 12.1 in the axial direction, with the normal of the surface preferably parallel to the displacement of the tip in the direction of the tip 3 (distal direction). The second capacitor plate 14 is formed as a hollow cylinder having a conductive plate surface on the inner side surface of the ground and a side surface of the hollow cylinder. The second capacitor plate 14 of the capacitive element has a surface normal extending at right angles to the displacement direction (positioning with respect to the center of the active pen 5, that is, facing the side conductive plate surface 12.2). Side plate surface 14.2 and the surface normal are parallel to the displacement direction, preferably in a direction away from the tip 3 (proximal direction), ie the second And an axial plate surface 14.1 facing the axial plate surface 12.1 of the capacitor plate. In the embodiment shown, the second capacitor plate 14 is formed by a housing 9.1, which has a metal coating on the inner wall of the housing 9.1 to achieve the capacitor surface. Capacitive element, the second capacitor portion having a first capacitor portion having a first capacitor surface A ₁ and the first capacitor distances x _1, the second capacitor surface A ₂ a second capacitor distance x ₂ It is divided into and. The first capacitor portion behaves as described in the first embodiment with the first capacitor distance x ₁ depending on the tip displacement d. The second capacitor portion has a behavior as described in the second embodiment in a state where the second capacitor surface A2 depends on the displacement d of the tip. The conductive plate surface 14.1 in the axial direction of the first capacitor plate and the conductive plate surface 14.2 on the side of the first capacitor plate have the same potential, and the conductive plate surface 12.1 in the axial direction of the second capacitor plate 12. And the lateral conductive plate surface 12.2 are at the same potential, the first capacitor portion and the second capacitor portion have C ₁ = k ₁ A ₁ / x ₁ (d) and C ₂ = K ₂ A ₂ (d) / x ₂ parallel circuit. Here, k ₁ and k ₂ are constant depending on the electric constant ε ₀ and are the relative static dielectric constant of the material between the capacitor plates 12 and 14. Accordingly, the capacitor has a capacitance value of C = C ₁ + C ₂ = k ₁ A ₁ / x ₁ (d) + k ₂ A ₂ (d) / x ₂ . The capacitive element combines the advantages of the behavior of a capacitive element having a capacitor distance depending on the displacement of the tip and a capacitive element having a capacitor surface depending on the displacement of the tip. Accordingly, the capacitor surface of the illustrated embodiment has an axial conductive plate surface 14.1 ((() of the first capacitor plate 14 that overlaps the axial conductive plate surface 12.1 of the second capacitor plate 14. In addition to D ₀ -D _i ) ² π), the lateral conductive plate surface 14.2 (first capacitor plate 12 overlapping the lateral conductive plate surface 12.2 of the second capacitor plate 12 ( The circumference is 2πD ₀ (h−d)), and only the latter changes depending on the displacement of the tip. The capacitor distance of the capacitive element is composed of an axial capacitor distance x ₁ (d) and a lateral capacitor distance x _2, and the former (only) varies depending on the displacement d of the tip. The distance between the conductive plate surface 14.2 on the side of the first capacitor plate 14 and the conductive plate surface 12.2 on the side of the second capacitor plate 12 remains constant with respect to the displacement d of the tip. And / or remain constant with respect to the axial conductive plate surface of the first capacitor plate 14 that overlaps the axial conductive plate surface 12.1 of the second capacitor plate 12. Functions 17 and 19 show the capacitive element according to the third embodiment with a capacitor face A ₁ defined by a ring with an outer diameter D ₀ and an inner diameter D ₁ . The function 17 corresponds to a diameter relationship of D _i / D ₀ = 0.3. The function 19 corresponds to a diameter relationship of D _i / D ₀ = 0.9. Functions 17 and 19 both correspond to the same height h. Functions 17 and 19 maintain an advantageous steep slope for tip displacements for small forces, but for tip displacements for large forces, these slopes are linear and therefore large tip displacements. Even in this case, the displacement of the tip can be determined by some desired constant error.

  The distances x1 and x2 only point to unrestricted distances in the direction of their corresponding distance vectors. In the illustrated embodiment, the distance vectors are perpendicular to each other, but other arrangements such as parallel or other angular orientations are possible.

  The illustrated embodiment is only an example for a capacitive element that changes its capacitor distance relative to its capacitor surface and tip displacement d. Furthermore, for example, this comprises surface normals with an angle between 1 ° and 89 ° or 91 ° and 179 °, respectively, with respect to the displacement of the tip (preferably parallel) ) It can also be realized by one capacitor part with two plate surfaces, so that the change of the tip displacement d changes the capacitor distance and the capacitor area where such capacitor elements overlap. Furthermore, it is possible to realize other capacitor elements. The effective capacitor area of the capacitor element changes, and the effective capacitor distance changes with the displacement of the tip.

  However, in another embodiment, a capacitor plate connected to the tip element 10 on the distal side of the active pen, and a fixed capacity plate on the proximal side of the active pen, It is also possible to realize a capacitive element comprising: and as a result, the distance between the capacitor plates makes it lesser to increase the displacement of the tip.

  Although the first and second capacitor plates are referred to as plates, this does not limit the shape of the plates relative to the linear capacitor plate and / or the flat capacitor plate with respect to the capacitor plate. One or both of the plates may have a curved capacitor surface, a circular capacitor surface, an elliptical capacitor surface, a triangular capacitor surface, or a polygonal capacitor surface. In all the described embodiments, even if the capacitor faces of both plates are arranged in parallel, this is not limiting, and capacitor plates with a more angular arrangement may also be possible.

  Alternatively, the force detection mechanism 9 includes other conversion means for converting the displacement of the tip portion into an electric signal that informs the displacement of the tip portion, for example, an inductive element using an inductance value depending on the displacement of the tip portion. May be used.

  The elastic element of the force detection mechanism 9 may be any elastic element, for example, any kind of spring. The elastic element is configured to apply a force to the tip element 10 that acts against (corrects) the force applied to the tip 3 over the force measurement range of the force sensor. Accordingly, the force detected by the force sensor is equal to or at least linearly proportional to the force of the elastic element acting on the tip element 10 at the time of detection. In other words, if the force of the elastic element acting on the tip element 10 (corresponding to different displacements of the tip) is different, the different force is measured by the force sensor. This is effective over the entire force detection range of the force sensor.

  In the embodiment shown, the elastic element is a leaf spring 15 as shown in FIGS. 4, 9, 10, 11, 12 and 13. The leaf spring 15 preferably has a ring shape, the two ring portions of the leaf spring 15 forming an elastic leaf portion 15.1, while the other two ring portions are of the leaf spring 15. It remains flat so as to form a fixed part 15.2. The leaf spring 15 seen from one side of the fixed part 15.2 forms a trapezoid with an elastic leaf part 15.1 forming a trapezoidal leg or side as shown in FIG. preferable. In other words, the elastic leaf portion 15.1 is bent or formed upward (in the direction of displacement of the tip) so that the leaf spring 15 has an elastic behavior in the direction of displacement of the tip. The leaf spring 15 is formed, for example, by punching a ring from one spring plate and bending or forming two ring portions in the direction of the normal of the surface of the spring plate (ring center axis). It is comprised so that it may form from a board. In one embodiment, the elastic spring plate portion 15.1 is symmetric with respect to a line passing through the two fixed portions 15.2. That is, the elastic spring plate portion corresponds to an isosceles trapezoid. However, the leaf spring 15 may be asymmetric. The leaf spring 15 may comprise only one or more than two elastic spring leaf portions 15.1. However, the leaf spring 15 may not have the fixing part 15.2 and / or the elastic spring part 15.1 may have other side shapes, for example triangular (except for the fixing part 15.2). It may have an elastic spring plate part, a round elastic spring plate part (for example, elliptical, polygonal, polynomial, circular, etc.). The ring shape in the illustrated embodiment is circular, but other ring shapes such as oval, triangle, rectangle, square, n-gon, etc. are possible. Alternatively, the leaf spring 15 may have a non-ring shape, preferably having two or more leaf plate portions. The spring plate portion may be formed of, for example, a plurality of spring plate fingers or a plurality of triangular portions.

  The fixing part 15.2 has a plurality of fixing elements 15.3. Is fixed to the housing 9.1 by means of spring plate fingers bent at right angles to the fixing part 15.2. The fixing element 15.3 may be configured to be formed from the same spring plate as the elastic spring plate portion 15.1 and / or the fixing portion 15.2. Those fixing elements 15.3 are inserted into the holes 16 of the housing 9.1. The hole 16 is located in the proximal base of a hollow cylinder formed in the housing 9.1. Accordingly, the fixed part 15.2 is supported by the proximal inner base surface of the housing 9.1 of the force detection mechanism 9. The spring plate portion 15.1 is supported by the second capacitor plate 12 under tension so that the spring plate portion 15.1 presses the tip element 10 with a small initial force at the initial position. When the force on the tip 3 exceeds the initial force, the tip element 10 moves in the displacement direction against the force of the leaf spring 15. The initial force is very small or zero. The leaf spring 15 is conductive, is made of, for example, metal, and is connected to the printed circuit board 8 via the housing 9.1. This can be achieved by a hole 16 in contact with the fixing element 15.3 or via a base surface and a fixing part inside the housing 9.1. However, other contact methods are possible. It is also possible to fix the fixing part 15.2 on the second capacitor plate 12 and fix the elastic spring plate part 15.1 on the housing 9.1. This solution has the advantage that the elastic element is used as a contact mechanism to the tip element 10 for the pen position signal and at the same time as an elastic element for the force detection mechanism. By supporting the elastic element in the housing 9.1 of the force detection mechanism 9, the force applied to the distal end portion 3 is transmitted to the housing 9.1 of the force detection mechanism 9, and this force detection mechanism is connected to the printed circuit board 8. Force is transmitted across the distal side and / or to the pen housing 6. Accordingly, the tip element 10 is not transmitted to the output terminal of the printed circuit board 8 for the pen position signal, but also to the entire side of the printed circuit board 8 and / or the pen housing 6, without transmitting the force to the printed circuit board 8. This solution uses an elastic element on one side so that it comes into contact with. Therefore, the damage on the printed circuit board 8 is effectively eliminated.

  The housing 9.1 is preferably formed by a distal half shell 9.11 and a proximal half shell 9.12. The distal half shell 9.11 shown in FIGS. 7 and 8 comprises a first capacitor plate 14 and a rod 11 of the tip element 10. The proximal half shell 9.12 supports the elastic element so that the force of the elastic element acts on the displacement of the tip portion of the tip element 10. The distal half shell 9.11 and the proximal half shell 9.12 cooperate to form a hollow cylinder. The distal half shell 9.11 and the proximal half shell 9.12 are preferably held together by the arm 8.2 of the printed circuit board 8. With this arrangement, the housing 9.1 for assembling the force detection mechanism 9 together with the elastic element and the tip element 10 can be opened.

  The stiffness S (d) of the elastic element preferably changes with the displacement d of the tip. This results in a non-linear elastic element with force F = −S (d) × d. The stiffness preferably increases with increasing tip displacement. This is an increasing stiffness increase or stepwise increase, for example, low stiffness from initial position to displacement of the first tip and between the displacement of the first tip and the displacement of the second or maximum tip. The second stiffness, including either. This makes it possible to cause a larger displacement of the tip with a smaller force, but a smaller displacement of the tip with a greater force. As a result, it is possible to widen the range of the force that can be detected without reducing the sensitivity of the same maximum tip displacement with a small tip displacement. However, it is also possible to use a constant stiffness S due to the linear elastic element that provides the force F = −S × d. The rigidity of the leaf spring 15 depends on various parameters of the leaf spring, in particular the length or radius of the spring plate portion, the angle α, the thickness t of the elastic spring plate portion 15.1 and / or the magnitude of the spring plate portion 15.1. Depends on the size. These parameters can be selected so that the leaf spring 15 exhibits a non-linear behavior due to the stiffness depending on the displacement d of the tip. This can be achieved by selecting those parameters that are different for the spring plate portions so that they have different (constant) stiffnesses that make the non-linear stiffness in the combined state of the at least two spring plate portions. . In the illustrated embodiment, each of the two spring leaf portions may have a different angle α and / or a different length or radius. Accordingly, at the initial position of the tip 3, only the first spring plate portion having a large angle α and / or a large length or radius acts against the force of the tip 3. At the moment when the tip element 10 is displaced due to the displacement of the first tip, the tip element 10 also contacts the second spring plate portion, and the stiffness of both spring plate portions is added to the increased stiffness. Therefore, such an arrangement can realize a rigidity S (d) having a step function. When the second spring plate portion contacts the tip element, the step moment over the tip displacement can be adjusted by the leaf spring parameters, which are determined from the initial position relative to the first tip displacement. Causes necessary tip displacement. The stiffness for tip displacement that is smaller than the displacement of the first tip can be controlled by parameters of the first spring plate portion, such as size and / or thickness t. The stiffness for displacement of the tip that is greater than the displacement of the first tip is a combination of the stiffness of both spring leaf portions and a second spring, such as size and / or thickness t. It can be controlled by the parameters of the plate part. The size and / or thickness of the second spring plate portion is preferably larger than those in the first spring plate portion. A composite step function (greater than 1 step) can be realized by a composite spring plate part (greater than 2). This can be achieved, for example, by arranging three or more spring plate portions, such as spring plate finger-like portions or triangles, in a plate spring. As the tip element 10 contacts each spring plate portion, each spring plate portion has a separate contact tip displacement. When the spring plate portion is a triangle or a finger-like body, the spring plate portion can be provided in a star (ring) shape. However, it is also possible to realize a leaf spring with constantly changing stiffness over the displacement of the tip. This can be achieved, for example, by a spiral spring plate portion having an increasing size or thickness or another stiffness that establishes parameters from the first contact area to the final contact area. .

  FIGS. 13A and 13B show an alternative embodiment of a leaf spring 21 as an elastic element, which can replace the leaf spring 15 of the previous figure. Also in this embodiment, the leaf spring 21 has a base portion 21.2 in the first plane and at least one elastic spring leaf portion 21.1. At least one resilient spring plate portion 21.1 is preferably cut (except for the bent edges) from a single spring plate material arranged in a first plane as shown in FIG. 13C. . The at least one elastic spring plate portion 21.1 is then bent at the bending edge, so that the surface of the at least one elastic spring plate portion 21.1 is the first as shown in FIG. 13A. It is arranged with at least one angle α less than the plane or the surface of the base part 21.2. Thus, the (respective) end of the at least one elastic spring part 21.1 has a constant height beyond the base part 21.2 or the first plane. Each end of the at least one elastic spring plate part 21.1 and the base part 21.2 are between the tip element 10 (here the capacitor plate 12) and the pen housing (here the housing 9 of the force detection mechanism). Thus, the force of the leaf spring 21 on the tip element 10 is arranged so as to change over the range of the force sensor relating to each displacement of the tip portion. Preferably, the at least one elastic spring plate portion comprises a plurality of elastic spring plate portions 21.1 (at least two). This makes it possible to realize a spring having a large force range at a very small height. From the plan view on the first plane, the leaf spring 21 has a center C and an outer peripheral side surface. The ends of the elastic spring plate portion 21.1 (with the height above the first plane) with the bending edge in the direction of the outer peripheral side of the plate spring 21 are shown in FIGS. 13A and 13B. As shown, the plurality of elastic spring plate portions 21.1 are each bent so as to point to the center C. The elastic spring plate portion 21.11 is preferably cut from the spring plate material between the center C and the bending edge, as shown in FIG. The shape of each of the elastic spring plate portions 21.11 is a triangle. In this way, the size d of the leaf spring 21 can be made extremely small despite the large force range of the leaf spring 21. In the embodiment shown, the leaf spring 21 has a peripheral base part 21.2, in which the elastic spring part 21.1 is arranged with a bent edge. The plurality of elastic spring plate portions 21. 1 preferably comprises at least one first elastic spring plate portion 21.11 and at least one second elastic spring plate portion 21.12. The (each) end of the at least one first elastic spring part 21.11 has a first height h1 and / or at least one first elastic spring part 21. 11 (each) preferably has a first stiffness. The (each) end of the at least one second elastic spring part 21.12 has a second height h2 and / or at least one second elastic spring part 21. The twelve (each) preferably have a second stiffness. The first height h1 is greater than the second height h2. However, but not necessarily, the first stiffness is preferably less than the second stiffness. Thereby, the first spring stiffness in the first compression range (<h1-h2) (equal to the number of first elastic spring plate portions 21.11 × first stiffness) and the second greater compression. Second stronger spring stiffness in range (> h1-h2) (number of first elastic spring plate portions 21.11 × first stiffness + number of second elastic spring plate portions 21.12 × first A leaf spring with a stiffness equal to two) can be realized. The second spring stiffness is stronger. The reason is that, in addition to the at least one first elastic spring plate portion 21.11, at least one second elastic spring plate portion 21.12 also acts on the tip element 10. Thereby, a non-linear leaf spring as described above having a step function can be realized. Different stiffnesses of the first and second elastic spring plate portions 21.11 and 21.12 can be realized with different shapes, here different lengths of the bending edges a1 and a2. The spring plate material is preferably a metal, for example copper or a metal containing copper, such as CuB2 (EN 1654).

  With the described leaf spring 21, a spring over the full force range of the force sensor with very small dimensions can be realized. The spring 21 preferably has a height (h1) smaller than 3 mm, preferably smaller than 2 mm, preferably smaller than 1.5 mm. The spring 21 preferably has a size (d) of less than 15 mm, preferably less than 10 mm, preferably less than 8 mm. The size (c) of the peripheral base portion 21.2 between the bending edge and the peripheral edge is preferably less than 1 mm, preferably less than 0.6 mm, preferably less than 0.4 mm. The difference between the first height h1 and the second height h2 is preferably less than 0.3, preferably less than 0.2 mm, preferably less than 0.15 mm.

  The force detection mechanism 9 and the force detection circuit together form a force sensor.

  The described embodiment of the pressure sensor of the active pen 15 outputs the pen position signal continuously, i.e. as disclosed in US Pat. This is particularly advantageous for active pens that are not phase synchronized by the touch device. Such an active pen is particularly advantageous in combination with a touch device that detects the position of the active contact that is passive and continuously outputs on the capacitive contact surface.

  Preferred features of this invention mean that this feature is the best way to carry out the invention, but said features can be replaced by other features without exceeding the scope of the claims. In other words, the scope of protection is not limited by the preferred features, but can be done in other ways.

  Various changes and modifications to the described embodiments of the invention will be apparent to those skilled in the art without departing from the scope of the invention as defined in the appended claims. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. It is.

  The present invention relates to an active position indicator, particularly an active pen, equipped with a pressure sensor.

  Touch devices are used in a variety of applications, where detection of the presence of objects is not limited, such as touchpads, touch panels, touch screens, or projected capacitive displays. Detection of the presence of such objects. The touch device can detect a passive object in contact with the touch device and determine the position of the contact. Thus, for example, user control can be performed. It is unsuitable that the quality of contact position detection decreases with the size of the contact surface. Therefore, the quality of the position detection of the tip of the pen may be detected only by a high detection error. Thus, an active position indicator, such as an active pen, includes an electrical circuit for supporting the touch device to detect the position of the active position indicator with low error. This can be achieved, for example, by capacitive coupling or inductive coupling. When using certain types of touch devices, such as capacitive touch devices or inductive touch devices, the same sensor for detecting passive touch detects electrical signals emitted from the tip of an active position indicator May be used for There are different types of active position indicators. There are active position indicators that synchronize with a window that emits an electrical signal to detect a particular active position indicator. There are other active position indicators by continuous transmission of electrical signals, ie without any synchronization in the active position indicator with respect to the touch device. There is an active position indicator that is activated by a battery or by an energy intake device for obtaining energy from the environment. There are also active position indicators without a power supply that are actuated like a transponder to obtain the power required for actuation from the transponder signal. Patent Document 1 shows a capacitive touch device with an active position indicator that emits continuously, for example, and the capacitive touch device has the same capacitive detection sensor for detecting passive and active touches. use.

  Another problem with good detection of interactions written on touch devices is how to understand the pressure applied by the pen. Some touch devices can directly detect the applied pressure. However, in most solutions with active pens, the pen includes a pressure sensor that detects the pressure applied to the tip and sends the detected pressure back to the touch device. However, the state of the art solution for pressure sensors has several disadvantages.

  Pressure sensors require movable parts, springs and often electrical connections of the movable parts to the printed circuit board. This increases time due to pen assembly, structural complexity and robustness.

  In particular, while drawing or writing, the force applied to the active pen can change from a very small force to a very high force. This increases the difficulty of detecting the tip force applied with high accuracy.

  One problem is the normal use of spiral springs or other elastic elements with a certain stiffness. Thus, a constant change in the force applied to the tip will result in the same displacement of the tip for weak and strong forces. The tip displacement is only minimal, so the realization can detect small forces with high accuracy, but it cannot detect large forces above a certain threshold, or it has a high force range up to high applied forces. Detect with low accuracy. Both alternatives are inadequate, so the less rigid spring is dominant with respect to weak forces and the rigid second spring is dominant with respect to large forces to expand the range of forces that can be detected by the pressure sensor Thus, some solutions include two springs with different stiffnesses. However, such a solution increases the complexity, size and robustness of the pressure sensor. Furthermore, spiral springs have the problem of being difficult to assemble and requiring a large space.

International Patent Application Publication No. 2014/174123 Specification

  Accordingly, an object of the present invention is to provide an active position indicator with a pressure sensor that overcomes the above-mentioned problems.

  It is an object of the present invention to provide an active position indicator with a pressure sensor that reduces the time to assemble a pen, reduces structural complexity, and increases robustness.

  It is an object of the present invention to provide an active position indicator having a low-complexity pressure sensor having a highly accurate force detection range in a small force state.

In one embodiment, these objects are achieved by an active position indicator, method and system according to the independent claims .

  The leaf spring is manufactured from a single spring leaf material and has the great advantage that it can be highly adapted to requirements such as shape, size and stiffness depending on the displacement of the tip. Furthermore, the leaf spring can easily come into contact with the displacement of the movable tip.

  The dependent claims relate to further advantageous embodiments.

In one embodiment, the position indicator comprises a position signal circuit that is connected to the movable tip element and is electrically coupled to the touch device by the tip. The elastic element is electrically conductive, and the position signal circuit is electrically connected to the movable tip element via the elastic element.

  This has the advantage that an element for contacting and an elastic element for acting against the force of the tip can be combined. This saves space and avoids the problem of contacting movable elements.

  In one embodiment, the elastic element is non-linear in stiffness depending on the tip displacement.

  Non-linear springs have the advantage that a constant change in force with a small force can result in a greater change in tip displacement compared to a constant change in force with a larger force.

  The invention is better understood and illustrated in the figures by the description of the examples given by way of example.

FIG. 3 shows a three-dimensional view of an embodiment of an active pen. FIG. 2 shows a three-dimensional view of the embodiment of FIG. 1 without an outer housing. FIG. 3 shows a three-dimensional view of an embodiment of a force sensor for an active pen. Fig. 4 shows a three-dimensional view of the force sensor of Fig. 3 with a transparent housing of the force sensor. The top view of the 2nd capacitor board of the capacitive element of the force sensor of FIG. 3 is shown. FIG. 4 shows a cross-sectional view of the capacitive element of the force sensor of FIG. 3 with a first capacitor plate and a second capacitor plate. FIG. 4 shows a three-dimensional view of the capacitive element of the force sensor of FIG. 3 with the first capacitor plate and the second capacitor plate in the initial position. FIG. 4 shows a plan view of a capacitive element of the force sensor of FIG. 3 provided with a first capacitor plate and a second capacitor plate. FIG. 4 shows a three-dimensional view of the force sensor housing of FIG. 3 with a spring. FIG. 4 shows a plan view of the housing of the force sensor of FIG. 3 with a spring. FIG. 10 shows a three-dimensional view of the spring of FIG. 9. Fig. 10 shows a first side view of the spring of Fig. 9; Fig. 10 shows a second side view of the spring of Fig. 9; FIG. 6 shows a plan view of an alternative embodiment of a spring. FIG. 13B illustrates a side view of an alternative embodiment of the spring of FIG. 13A. FIG. 13B illustrates a production stage of an alternative embodiment of the spring of FIG. 13A. 4 shows a curve showing the capacitance values of different capacitive elements with respect to the force applied to the tip 3.

  1 to 13 show an embodiment of an active pen 5. Everything disclosed by the active pens described below is applicable to all other types of active position indicators.

  The active pen 5 includes a pen housing 6, a battery 7, a printed circuit board 8, a force sensor and a tip element 10 having a tip 3.

  The pen housing 6 preferably seals the battery 7, the printed circuit board 8, and the force detection mechanism 9 of the force sensor. The pen housing 6 includes the tip element 10 such that the tip 3 is disposed outside the pen housing 6 and is connected to the internal chamber of the pen housing 6 via the rod-like body 11 of the tip element 10. It is preferable to provide the opening part. The opening of the pen housing 6 preferably guides the rod 11 of the tip element 10 only so that the tip element 10 can be moved in the displacement direction. However, it is also possible to detect forces in different directions. The pen housing 6 has a cylindrical shape, and the displacement direction is preferably parallel to the longitudinal cylindrical axis. According to the definition, the side / end of the active pen 5 with the tip 3 is named the distal side / end and the opposite side / end of the active pen 5 in the displacement direction is proximal Called side / end. In the illustrated embodiment, the pen housing 6 comprises a battery 6.1, a cylindrical part 6.1 having a printed circuit board 8 and a force detection mechanism 9, a conical part 6.2 having said opening and tip elements and a cap 6. 3 is provided. Furthermore, the tubular part 6.1 comprises a power button 6.4 configured to interact with the power switch 8.1 on the printed circuit board 8. The conical part 6.2 is attached at its proximal end to the distal end of the tubular part 6.1. The distal end of the cone 6.2 is provided with an opening for the tip element 10. The cone 6.2 preferably has a conical shape that narrows from the proximal end to the distal end. The proximal end of the cylindrical housing 6.1 is attached to a cap 6.3 that closes the pen housing 6 at the proximal end. In a preferred embodiment, the cap 6.3 should be removable for replacing the battery 7, for example by a fastener or a threading mechanism. In addition, the cap 6.3 should generate the necessary contact pressure to connect the battery terminal of the printed circuit board 8 to the power supply terminal.

  The illustrated embodiment of the active pen 5 is operated by a battery 7 as a power source. However, any other means of supplying the necessary power may alternatively be used. For example, the battery 7 can take in energy from ambient conditions, for example, light, temperature, electromagnetic waves (eg, from a touch device), electrical coupling (eg, with a touch device), pen movement, etc. It can be replaced by a mechanism.

  The printed circuit board 8 comprises all or at least most of the electronic circuit components of the active pen 5 in this embodiment. The printed circuit board 8 has a longitudinal axis parallel to the longitudinal axis of the cylindrical part 6.1 of the active pen 5 or of the pen housing 6. The size of the printed circuit board 8 corresponds in one embodiment to the inner diameter of the pen housing 6, in particular the cylindrical housing 6.1. In the illustrated embodiment, the printed circuit board 8 is held by or at the distal end of the force sensing mechanism 9 and / or the proximal end of the power terminal 8.3 of the printed circuit board 8. Hold. The housing 9 of the force detection mechanism is such that the printed circuit board 8 is additionally fixed in all radial directions via the housing 9.1 of the force detection mechanism 9 and / or via the power supply terminal 8.3. .1 and / or the power supply terminal 8.3 has a cylindrical shape corresponding to the internal shape of the hollow cylinder provided by the housing 6. However, the printed circuit board 8 may be directly fixed in the housing 6 by, for example, a rail for the printed circuit board 8. The printed circuit board 8 forms two arms 8.2 at its distal end configured to hold the housing 9.1 of the force detection mechanism 9. In order to allow the maximum distance between the two arms 8.2, the arms are on both sides of the printed circuit board 8 with a thickness that should resist the expected stress on the housing 9.1 of the force detection mechanism. Is arranged. The housing 9.1 of the force detection mechanism can be provided with two recesses 13 (shown in FIGS. 3 to 5 and FIGS. 7 to 10) to constitute the two arms 8.2 of the printed circuit board 8. The dimensions of the arm 8.2 and the recess 13 are preferably designed so that the arm 8.2 occupies the recess 13, and as a result, the housing 9.1 is in a radial direction relative to the direction of displacement of the tip 3. I can't move. The side surface of the force detection mechanism housing 9.1 (the surface generally in the radial direction with respect to the longitudinal axis of the housing 6) is in contact with the side surface of the printed circuit board 8. The distal end of the arm 8.2 may be provided with a hook in order to fix the force detection mechanism housing 9.1 in the longitudinal direction of the printed circuit board 8 and to realize a snap-fit fixing. . However, other fixations are possible.

  The printed circuit board 8 preferably includes a position signal circuit for generating and outputting a pen position signal. The pen position signal is preferably a periodic signal, such as a sine wave signal and / or a cosine wave signal, and the constant frequency is suitable for transmission and detection in a touch device. Such a position signal circuit includes, for example, an oscillator and an amplifier. The output portion of the position signal circuit is preferably connected to at least one output terminal of the printed circuit board 8. The output portion of the printed circuit board 8 is preferably conductively connected to the tip portion 3 for supplying a pen position signal generated at the tip portion 3. A signal applied to the tip 3 creates electrical coupling with the touch device. Such coupling is preferably capacitive coupling and / or inductive coupling, but may be any electromagnetic emission that can be received by the touch device. The output terminal is preferably conductively connected to a conductive elastic element that holds the tip element 10 in its initial position, for example a metal spring that is conductively connected to the tip element 10. This solves the problem of bringing the movable tip element 10 into contact with the fixed printed circuit board 8.

  The printed circuit board 8 preferably includes a force detection circuit of a force sensor for detecting a force applied to the tip 3 based on an electronic feedback signal received from the force detection mechanism 9. The input portion of the force detection circuit is preferably conductively connected to at least one feedback input terminal of the circuit board 8. At least one feedback input terminal of the circuit board 8 is preferably disposed on at least one of the two arms 8.2 configured to contact the feedback terminal of the force detection mechanism 9. Accordingly, at least one recess 13 has a conductive surface, which is in conductive contact with the conductive surface of at least one arm 8.2 with at least one feedback input terminal. There are preferably two input terminals for the feedback signal of the force detection mechanism 9 in each of the two arms 8.2 of the printed circuit board 8. In the embodiment shown, the force detection mechanism 9 comprises a variable capacitive element having a capacitance value that depends on the displacement of the tip (described below). In the illustrated embodiment, the pen position signal is sent to the second capacitor plate 12 of the capacitive element and the feedback signal is sent from the first capacitor plate 14 of the capacitive element to the force detection circuit. Since the pen position signal has a fixed frequency or at least a known frequency, the complex resistance of the path from the second capacitor plate 12 to the force detection circuit depends on the capacitance value of the capacitive element. Therefore, the capacitance value of the capacitive element, which itself depends only on the tip displacement, can be determined by the feedback signal. The force detection circuit measures a value for the complex resistance, and this value is provided by a capacitive element that can be processed into a value related to the force, for example by means of a lookup table. An example for determining the complex resistance can be determined, for example, by rectifying the feedback signal and applying a low pass filter to the feedback signal. This gives a value for the amplification of the feedback signal giving a measurement for the complex resistance. Instead of the pen position signal, other signals applied by the capacitive element can be used to detect the capacitance value. However, other measurement methods for other electronic values depending on the capacitance value or the displacement of the tip element are also determined and / or converted into force values in the force detection circuit.

  Furthermore, the printed circuit board 8 may include a force data transfer circuit for transferring the detected force (force data) that causes the tip 3 to act on the touch device. In one embodiment, the force data transfer circuit is connected to the tip 3 for transferring force data to the touch device by electrically coupling the tip 3 with the touch device. The force data can be transferred during the period of the pen position signal and / or the force data can be modulated continuously or in a data transfer window for the pen position signal. Different modulations such as frequency, amplification or other modes of modulation may be used here. In another embodiment, the force data transfer circuit is connected to an antenna (rather than the tip 3) for transferring force data to the touch device. In other embodiments, force data may be transferred to the touch device via a wired connection.

  However, the present invention is not limited to the printed circuit board 8. Other circuit boards or other implementations of electronic circuitry may also be used to fulfill the electronic functionality of the active pen.

  The tip element 10 comprises a tip 3 at the distal end and a first capacitor plate 12 of a capacitive element at the proximal end. The first capacitor plate 12 is also part of the force detection mechanism 9 which will be described in more detail later. The tip 3 and the first capacitor plate 12 are connected by a rod-like body 11. The tip 3 is provided with a conductive material for outputting a pen position signal received from the position signal circuit. In the embodiment shown, the tip 3 comprises a conductive core 3 ′, preferably a metal core as shown in FIGS. 3 and 4, which is covered by a protective cap, The protective cap is configured to pass outgoing pen position signals and / or is configured to avoid any damage to the touch screen. In order to guide the position signal of the pen to the tip 3, the rod 11 is also preferably provided with a conductive material, preferably a metal, or made of a conductive material, preferably a metal. In an alternative embodiment, the bar 11 is made of a non-conductive material and includes a conductor for guiding the pen position signal from the position signal circuit to the tip 3. Such a conductor may be a conductive core of the rod-shaped body 11. The first capacitor plate 12 is also preferably made of a conductive material, preferably metal. However, it is also possible to make the first capacitor plate 12 from a non-conductive material with a metal coating or metal surface for at least one capacitor surface of the capacitive element of the force detection mechanism 9 described later. is there. The tip element 10 is movably supported so that the tip element 10 can be moved at least in the displacement direction. Support can be provided by the housing 6, for example by an opening in the housing 6, and / or by a force detection mechanism 9. When there is no force applied to the tip 3, the tip element 10 is arranged at the initial position. Furthermore, the tip element 10 is arranged to be moved from the initial position by the displacement of the tip portion depending on the force applied to the tip portion 3. The active pen 5 may be provided with a maximum stop element for the tip element 10 that limits the tip displacement to the maximum tip displacement. Such a maximum stopper element can be provided in the housing 6 or the force detection mechanism 9.

  The force detection mechanism 9 resists a capacitive element having a capacitance value depending on the displacement of the tip, and a force applied to the tip 3 for holding the tip element in the initial position and / or in the displacement direction. And an elastic element.

  In the embodiment shown, the capacitive element comprises a first capacitor plate 14 and a second capacitor plate 12. The first capacitor plate 14 is preferably fixed with respect to the housing 6 and / or the housing 9.1 of the force detection mechanism 9, but the second capacitor plate 12 moves depending on the displacement of the tip. Alternatively, it is also important that there is a relative movement of the first and second capacitor plates 14 and 12 relative to each other. In the illustrated embodiment, the second capacitor plate 12 is positioned at the initial position of the tip element 10 at a minimum distance relative to the first capacitor plate 14 and the first and second The first capacitor plate 14 is arranged so that the distance between the capacitor plates 14 and 12 increases linearly with the displacement of the tip. In the illustrated embodiment, the minimum distance is zero so that the first and second capacitor plates 14 and 12 are conductively connected and the initial position of the tip element 10 is easily detectable. is there. However, it is possible that the minimum distance between the capacitor plates is not equal to zero. This avoids short circuits due to increased power consumption. This can also be used to adjust the behavior of the capacitance value of the capacitive element. The reason is that this reduces the initial value of the capacitance value at the initial position of the tip 3 (if there is another capacitive part with the linear behavior described later, this means that Increase linear behavior). Between the first capacitor plate 14 and the second capacitor plate 12, an insulating material or dielectric material for realizing a non-zero initial position between the two capacitor plates 12 and 14 is disposed. This can be achieved by coating the surface 12.1 or 12.2 with an insulator or dielectric coating. In one embodiment, the first capacitor plate 14 is disposed on the distal side (near the tip 3) and the second capacitor plate 12 is disposed on the proximal side (far from the tip 3). ing. This is achieved by guiding the rod 11 through the first capacitor plate 14, preferably in the center.

  In one embodiment, the capacitive element has a capacitance value that depends on the displacement d of the tip. The capacitance value C of the capacitive element is calculated based on the capacitor area A of the capacitive element and the capacitor distance x of the capacitive element. If the capacitance component is given by two parallel planes with capacitor area A and capacitor distance x, the capacitance value is proportional to capacitor area A divided by capacitor distance x, ie A / x.

State in the first embodiment of the capacitor, the capacitor plate, the normal is parallel to the displacement direction of the distal end portion 3, the capacitor distance x ₁ is proportional or directly equal to the displacement d of the distal portion in, and a metal surface overlaps and faces on the plate surfaces a _1. This gives a capacitance value C ₁ that is directly proportional to the inverse 1 / d of the tip displacement. Since the complex resistivity Z ₁ is directly proportional to the inverse of the capacitance value, the complex resistivity is in this case linearly proportional to d. However, this has the disadvantage that a small displacement d of the tip can be detected with the same absolute error as a large displacement d of the tip. However, since it is desired to have high sensitivity due to the small displacement of the tip, therefore, for a small displacement d of the tip, the relative error becomes large and such a solution is not desired. FIG. 14 shows the capacitance values of different capacitive elements with respect to the force applied to the tip 3 (with an elastic element having a constant stiffness). Functions 18 and 20 show a capacitor according to the first embodiment with an outer diameter D ₀ and the inner diameter D ₁ capacitor surface A1 defined by a ring having a. The function 18 corresponds to a diameter relationship of D ₁ / D ₀ = 0.3, and the function 20 corresponds to a diameter relationship of D ₁ / D ₀ = 0.9. Functions 18 and 20 have steep tip displacements for small forces, but these gradients are subject to tip displacements for increasing forces so that the detection error for large forces is quite large. For always become flatter.

In the second embodiment of the capacitive element, the normal is perpendicular to the displacement direction of the tip 3 and the capacitor surface A2 is equal to or directly proportional to the displacement d of the tip. The plate has a metal surface facing the plate surface. Capacitor area A ₂ overlapping is to increase or decrease the displacement d and linear tip, the two faces of the two capacitor plates are arranged, the distance x ₂ remains constant. Thus, the capacitance value C ₂ which is directly proportional to the displacement d of the tip portion is obtained. Complex resistivity Z _2, since directly proportional to the reciprocal of the capacitance value, in this case the complex resistivity, is linearly proportional to the 1 / d. Thus, small changes with small displacement of the tip can be detected fairly accurately compared to changes with large displacement of the tip due to higher capacitance value changes. However, this method also has disadvantages. The reason for this is that the characteristic for detecting a change due to a large displacement of the tip can now only be detected with a large error due to the substantially flat behavior of the capacitance value.

A third embodiment of the capacitive element provides the first and second in order to achieve the behavior of the capacitance value over the tip displacement d, which changes faster than the large tip displacement, at a small tip displacement. Combining the advantages of both embodiments, this does not have the negative impact of the second embodiment of the capacitive element. This is achieved by a capacitive element whose capacitor area and capacitor distance both change depending on the displacement d of the tip. Such an achievement is proved by the active pen 5. Accordingly, the first capacitor plate 12 has a lateral conductive plate surface 12.2 in a state where the normal of the surface is perpendicular to the displacement of the tip portion (positioning with respect to the outside of the active pen). A conductive plate surface 12.1 in the axial direction, with the normal of the surface preferably parallel to the displacement of the tip in the direction of the tip 3 (distal direction). The second capacitor plate 14 is formed as a hollow cylinder having a conductive plate surface on the inner side surface of the ground and a side surface of the hollow cylinder. The second capacitor plate 14 of the capacitive element has a surface normal extending at right angles to the displacement direction (positioning with respect to the center of the active pen 5, that is, facing the side conductive plate surface 12.2). Side plate surface 14.2 and the surface normal are parallel to the displacement direction, preferably in a direction away from the tip 3 (proximal direction), ie the second And an axial plate surface 14.1 facing the axial plate surface 12.1 of the capacitor plate. In the embodiment shown, the second capacitor plate 14 is formed by a housing 9.1, which has a metal coating on the inner wall of the housing 9.1 to achieve the capacitor surface. Capacitive element, the second capacitor portion having a first capacitor portion having a first capacitor surface A ₁ and the first capacitor distances x _1, the second capacitor surface A ₂ a second capacitor distance x ₂ It is divided into and. The first capacitor portion behaves as described in the first embodiment with the first capacitor distance x ₁ depending on the tip displacement d. The second capacitor portion has a behavior as described in the second embodiment in a state where the second capacitor surface A2 depends on the displacement d of the tip. The conductive plate surface 14.1 in the axial direction of the first capacitor plate and the conductive plate surface 14.2 on the side of the first capacitor plate have the same potential, and the conductive plate surface 12.1 in the axial direction of the second capacitor plate 12. And the lateral conductive plate surface 12.2 are at the same potential, the first capacitor portion and the second capacitor portion have C ₁ = k ₁ A ₁ / x ₁ (d) and C ₂ = K ₂ A ₂ (d) / x ₂ parallel circuit. Here, k ₁ and k ₂ are constant depending on the electric constant ε ₀ and are the relative static dielectric constant of the material between the capacitor plates 12 and 14. Accordingly, the capacitor has a capacitance value of C = C ₁ + C ₂ = k ₁ A ₁ / x ₁ (d) + k ₂ A ₂ (d) / x ₂ . The capacitive element combines the advantages of the behavior of a capacitive element having a capacitor distance depending on the displacement of the tip and a capacitive element having a capacitor surface depending on the displacement of the tip. Accordingly, the capacitor surface of the illustrated embodiment has an axial conductive plate surface 14.1 ((() of the first capacitor plate 14 that overlaps the axial conductive plate surface 12.1 of the second capacitor plate 14. In addition to D ₀ -D _i ) ² π), the lateral conductive plate surface 14.2 (first capacitor plate 12 overlapping the lateral conductive plate surface 12.2 of the second capacitor plate 12 ( The circumference is 2πD ₀ (h−d)), and only the latter changes depending on the displacement of the tip. The capacitor distance of the capacitive element is composed of an axial capacitor distance x ₁ (d) and a lateral capacitor distance x _2, and the former (only) varies depending on the displacement d of the tip. The distance between the conductive plate surface 14.2 on the side of the first capacitor plate 14 and the conductive plate surface 12.2 on the side of the second capacitor plate 12 remains constant with respect to the displacement d of the tip. And / or remain constant with respect to the axial conductive plate surface of the first capacitor plate 14 that overlaps the axial conductive plate surface 12.1 of the second capacitor plate 12. Functions 17 and 19 show the capacitive element according to the third embodiment with a capacitor face A ₁ defined by a ring with an outer diameter D ₀ and an inner diameter D ₁ . The function 17 corresponds to a diameter relationship of D _i / D ₀ = 0.3. The function 19 corresponds to a diameter relationship of D _i / D ₀ = 0.9. Functions 17 and 19 both correspond to the same height h. Functions 17 and 19 maintain an advantageous steep slope for tip displacements for small forces, but for tip displacements for large forces, these slopes are linear and therefore large tip displacements. Even in this case, the displacement of the tip can be determined by some desired constant error.

  The distances x1 and x2 only point to unrestricted distances in the direction of their corresponding distance vectors. In the illustrated embodiment, the distance vectors are perpendicular to each other, but other arrangements such as parallel or other angular orientations are possible.

  The illustrated embodiment is only an example for a capacitive element that changes its capacitor distance relative to its capacitor surface and tip displacement d. Furthermore, for example, this comprises surface normals with an angle between 1 ° and 89 ° or 91 ° and 179 °, respectively, with respect to the displacement of the tip (preferably parallel) ) It can also be realized by one capacitor part with two plate surfaces, so that the change of the tip displacement d changes the capacitor distance and the capacitor area where such capacitor elements overlap. Furthermore, it is possible to realize other capacitor elements. The effective capacitor area of the capacitor element changes, and the effective capacitor distance changes with the displacement of the tip.

  However, in another embodiment, a capacitor plate connected to the tip element 10 on the distal side of the active pen, and a fixed capacity plate on the proximal side of the active pen, It is also possible to realize a capacitive element comprising: and as a result, the distance between the capacitor plates makes it lesser to increase the displacement of the tip.

  Although the first and second capacitor plates are referred to as plates, this does not limit the shape of the plates relative to the linear capacitor plate and / or the flat capacitor plate with respect to the capacitor plate. One or both of the plates may have a curved capacitor surface, a circular capacitor surface, an elliptical capacitor surface, a triangular capacitor surface, or a polygonal capacitor surface. In all the described embodiments, even if the capacitor faces of both plates are arranged in parallel, this is not limiting, and capacitor plates with a more angular arrangement may also be possible.

  Alternatively, the force detection mechanism 9 includes other conversion means for converting the displacement of the tip portion into an electric signal that informs the displacement of the tip portion, for example, an inductive element using an inductance value depending on the displacement of the tip portion. May be used.

  The elastic element of the force detection mechanism 9 may be any elastic element, for example, any kind of spring. The elastic element is configured to apply a force to the tip element 10 that acts against (corrects) the force applied to the tip 3 over the force measurement range of the force sensor. Accordingly, the force detected by the force sensor is equal to or at least linearly proportional to the force of the elastic element acting on the tip element 10 at the time of detection. In other words, if the force of the elastic element acting on the tip element 10 (corresponding to different displacements of the tip) is different, the different force is measured by the force sensor. This is effective over the entire force detection range of the force sensor.

  In the embodiment shown, the elastic element is a leaf spring 15 as shown in FIGS. 4, 9, 10, 11, 12 and 13. The leaf spring 15 preferably has a ring shape, the two ring portions of the leaf spring 15 forming an elastic leaf portion 15.1, while the other two ring portions are of the leaf spring 15. It remains flat so as to form a fixed part 15.2. The leaf spring 15 seen from one side of the fixed part 15.2 forms a trapezoid with an elastic leaf part 15.1 forming a trapezoidal leg or side as shown in FIG. preferable. In other words, the elastic leaf portion 15.1 is bent or formed upward (in the direction of displacement of the tip) so that the leaf spring 15 has an elastic behavior in the direction of displacement of the tip. The leaf spring 15 is formed, for example, by punching a ring from one spring plate and bending or forming two ring portions in the direction of the normal of the surface of the spring plate (ring center axis). It is comprised so that it may form from a board. In one embodiment, the elastic spring plate portion 15.1 is symmetric with respect to a line passing through the two fixed portions 15.2. That is, the elastic spring plate portion corresponds to an isosceles trapezoid. However, the leaf spring 15 may be asymmetric. The leaf spring 15 may comprise only one or more than two elastic spring leaf portions 15.1. However, the leaf spring 15 may not have the fixing part 15.2 and / or the elastic spring part 15.1 may have other side shapes, for example triangular (except for the fixing part 15.2). It may have an elastic spring plate part, a round elastic spring plate part (for example, elliptical, polygonal, polynomial, circular, etc.). The ring shape in the illustrated embodiment is circular, but other ring shapes such as oval, triangle, rectangle, square, n-gon, etc. are possible. Alternatively, the leaf spring 15 may have a non-ring shape, preferably having two or more leaf plate portions. The spring plate portion may be formed of, for example, a plurality of spring plate fingers or a plurality of triangular portions.

  The fixing part 15.2 has a plurality of fixing elements 15.3. Is fixed to the housing 9.1 by means of spring plate fingers bent at right angles to the fixing part 15.2. The fixing element 15.3 may be configured to be formed from the same spring plate as the elastic spring plate portion 15.1 and / or the fixing portion 15.2. Those fixing elements 15.3 are inserted into the holes 16 of the housing 9.1. The hole 16 is located in the proximal base of a hollow cylinder formed in the housing 9.1. Accordingly, the fixed part 15.2 is supported by the proximal inner base surface of the housing 9.1 of the force detection mechanism 9. The spring plate portion 15.1 is supported by the second capacitor plate 12 under tension so that the spring plate portion 15.1 presses the tip element 10 with a small initial force at the initial position. When the force on the tip 3 exceeds the initial force, the tip element 10 moves in the displacement direction against the force of the leaf spring 15. The initial force is very small or zero. The leaf spring 15 is conductive, is made of, for example, metal, and is connected to the printed circuit board 8 via the housing 9.1. This can be achieved by a hole 16 in contact with the fixing element 15.3 or via a base surface and a fixing part inside the housing 9.1. However, other contact methods are possible. It is also possible to fix the fixing part 15.2 on the second capacitor plate 12 and fix the elastic spring plate part 15.1 on the housing 9.1. This solution has the advantage that the elastic element is used as a contact mechanism to the tip element 10 for the pen position signal and at the same time as an elastic element for the force detection mechanism. By supporting the elastic element in the housing 9.1 of the force detection mechanism 9, the force applied to the distal end portion 3 is transmitted to the housing 9.1 of the force detection mechanism 9, and this force detection mechanism is connected to the printed circuit board 8. Force is transmitted across the distal side and / or to the pen housing 6. Accordingly, the tip element 10 is not transmitted to the output terminal of the printed circuit board 8 for the pen position signal, but also to the entire side of the printed circuit board 8 and / or the pen housing 6, without transmitting the force to the printed circuit board 8. This solution uses an elastic element on one side so that it comes into contact with. Therefore, the damage on the printed circuit board 8 is effectively eliminated.

  The housing 9.1 is preferably formed by a distal half shell 9.11 and a proximal half shell 9.12. The distal half shell 9.11 shown in FIGS. 7 and 8 comprises a first capacitor plate 14 and a rod 11 of the tip element 10. The proximal half shell 9.12 supports the elastic element so that the force of the elastic element acts on the displacement of the tip portion of the tip element 10. The distal half shell 9.11 and the proximal half shell 9.12 cooperate to form a hollow cylinder. The distal half shell 9.11 and the proximal half shell 9.12 are preferably held together by the arm 8.2 of the printed circuit board 8. With this arrangement, the housing 9.1 for assembling the force detection mechanism 9 together with the elastic element and the tip element 10 can be opened.

  The stiffness S (d) of the elastic element preferably changes with the displacement d of the tip. This results in a non-linear elastic element with force F = −S (d) × d. The stiffness preferably increases with increasing tip displacement. This is an increasing stiffness increase or stepwise increase, for example, low stiffness from initial position to displacement of the first tip and between the displacement of the first tip and the displacement of the second or maximum tip. The second stiffness, including either. This makes it possible to cause a larger displacement of the tip with a smaller force, but a smaller displacement of the tip with a greater force. As a result, it is possible to widen the range of the force that can be detected without reducing the sensitivity of the same maximum tip displacement with a small tip displacement. However, it is also possible to use a constant stiffness S due to the linear elastic element that provides the force F = −S × d.

  The rigidity of the leaf spring 15 depends on various parameters of the leaf spring, in particular the length or radius of the spring plate portion, the angle α, the thickness t of the elastic spring plate portion 15.1 and / or the magnitude of the spring plate portion 15.1. Depends on the size. These parameters can be selected so that the leaf spring 15 exhibits a non-linear behavior due to the stiffness depending on the displacement d of the tip. This can be achieved by selecting those parameters that are different for the spring plate portions so that they have different (constant) stiffnesses that make the non-linear stiffness in the combined state of the at least two spring plate portions. . In the illustrated embodiment, each of the two spring leaf portions may have a different angle α and / or a different length or radius. Accordingly, at the initial position of the tip 3, only the first spring plate portion having a large angle α and / or a large length or radius acts against the force of the tip 3. At the moment when the tip element 10 is displaced due to the displacement of the first tip, the tip element 10 also contacts the second spring plate portion, and the stiffness of both spring plate portions is added to the increased stiffness. Therefore, such an arrangement can realize a rigidity S (d) having a step function. When the second spring plate portion contacts the tip element, the step moment over the tip displacement can be adjusted by the leaf spring parameters, which are determined from the initial position relative to the first tip displacement. Causes necessary tip displacement. The stiffness for tip displacement that is smaller than the displacement of the first tip can be controlled by parameters of the first spring plate portion, such as size and / or thickness t. The stiffness for displacement of the tip that is greater than the displacement of the first tip is a combination of the stiffness of both spring leaf portions and a second spring, such as size and / or thickness t. It can be controlled by the parameters of the plate part. The size and / or thickness of the second spring plate portion is preferably larger than those in the first spring plate portion. A composite step function (greater than 1 step) can be realized by a composite spring plate part (greater than 2). This can be achieved, for example, by arranging three or more spring plate portions, such as spring plate finger-like portions or triangles, in a plate spring. As the tip element 10 contacts each spring plate portion, each spring plate portion has a separate contact tip displacement. When the spring plate portion is a triangle or a finger-like body, the spring plate portion can be provided in a star (ring) shape. However, it is also possible to realize a leaf spring with constantly changing stiffness over the displacement of the tip. This can be achieved, for example, by a spiral spring plate portion having an increasing size or thickness or another stiffness that establishes parameters from the first contact area to the final contact area. .

  FIGS. 13A and 13B show an alternative embodiment of a leaf spring 21 as an elastic element, which can replace the leaf spring 15 of the previous figure. Also in this embodiment, the leaf spring 21 has a base portion 21.2 in the first plane and at least one elastic spring leaf portion 21.1. At least one resilient spring plate portion 21.1 is preferably cut (except for the bent edges) from a single spring plate material arranged in a first plane as shown in FIG. 13C. . The at least one elastic spring plate portion 21.1 is then bent at the bending edge, so that the surface of the at least one elastic spring plate portion 21.1 is the first as shown in FIG. 13A. It is arranged with at least one angle α less than the plane or the surface of the base part 21.2. Thus, the (respective) end of the at least one elastic spring part 21.1 has a constant height beyond the base part 21.2 or the first plane. Each end of the at least one elastic spring plate part 21.1 and the base part 21.2 are between the tip element 10 (here the capacitor plate 12) and the pen housing (here the housing 9 of the force detection mechanism). Thus, the force of the leaf spring 21 on the tip element 10 is arranged so as to change over the range of the force sensor relating to each displacement of the tip portion. Preferably, the at least one elastic spring plate portion comprises a plurality of elastic spring plate portions 21.1 (at least two). This makes it possible to realize a spring having a large force range at a very small height. From the plan view on the first plane, the leaf spring 21 has a center C and an outer peripheral side surface. The ends of the elastic spring plate portion 21.1 (with the height above the first plane) with the bending edge in the direction of the outer peripheral side of the plate spring 21 are shown in FIGS. 13A and 13B. As shown, the plurality of elastic spring plate portions 21.1 are each bent so as to point to the center C. The elastic spring plate portion 21.11 is preferably cut from the spring plate material between the center C and the bending edge, as shown in FIG. The shape of each of the elastic spring plate portions 21.11 is a triangle. In this way, the size d of the leaf spring 21 can be made extremely small despite the large force range of the leaf spring 21. In the embodiment shown, the leaf spring 21 has a peripheral base part 21.2, in which the elastic spring part 21.1 is arranged with a bent edge. The plurality of elastic spring plate portions 21. 1 preferably comprises at least one first elastic spring plate portion 21.11 and at least one second elastic spring plate portion 21.12. The (each) end of the at least one first elastic spring part 21.11 has a first height h1 and / or at least one first elastic spring part 21. 11 (each) preferably has a first stiffness. The (each) end of the at least one second elastic spring part 21.12 has a second height h2 and / or at least one second elastic spring part 21. The twelve (each) preferably have a second stiffness. The first height h1 is greater than the second height h2. However, but not necessarily, the first stiffness is preferably less than the second stiffness. Thereby, the first spring stiffness in the first compression range (<h1-h2) (equal to the number of first elastic spring plate portions 21.11 × first stiffness) and the second greater compression. Second stronger spring stiffness in range (> h1-h2) (number of first elastic spring plate portions 21.11 × first stiffness + number of second elastic spring plate portions 21.12 × first A leaf spring with a stiffness equal to two) can be realized. The second spring stiffness is stronger. The reason is that, in addition to the at least one first elastic spring plate portion 21.11, at least one second elastic spring plate portion 21.12 also acts on the tip element 10. Thereby, a non-linear leaf spring as described above having a step function can be realized. Different stiffnesses of the first and second elastic spring plate portions 21.11 and 21.12 can be realized with different shapes, here different lengths of the bending edges a1 and a2. The spring plate material is preferably a metal, for example copper or a metal containing copper, such as CuB2 (EN 1654).

  With the described leaf spring 21, a spring over the full force range of the force sensor with very small dimensions can be realized. The spring 21 preferably has a height (h1) smaller than 3 mm, preferably smaller than 2 mm, preferably smaller than 1.5 mm. The spring 21 preferably has a size (d) of less than 15 mm, preferably less than 10 mm, preferably less than 8 mm. The size (c) of the peripheral base portion 21.2 between the bending edge and the peripheral edge is preferably less than 1 mm, preferably less than 0.6 mm, preferably less than 0.4 mm. The difference between the first height h1 and the second height h2 is preferably less than 0.3, preferably less than 0.2 mm, preferably less than 0.15 mm.

  The force detection mechanism 9 and the force detection circuit together form a force sensor.

  The described embodiment of the pressure sensor of the active pen 15 outputs the pen position signal continuously, i.e. as disclosed in US Pat. This is particularly advantageous for active pens that are not phase synchronized by the touch device. Such an active pen is particularly advantageous in combination with a touch device that detects the position of the active contact that is passive and continuously outputs on the capacitive contact surface. Such a touch device is disclosed in Patent Document 1 and is incorporated by reference.

  Preferred features of this invention mean that this feature is the best way to carry out the invention, but said features can be replaced by other features without exceeding the scope of the claims. In other words, the scope of protection is not limited by the preferred features, but can be done in other ways.

  Various changes and modifications to the described embodiments of the invention will be apparent to those skilled in the art without departing from the scope of the invention as defined in the appended claims. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. It is.

Claims (19)

A movable tip element (10), the tip element depending on the force acting on the tip (3) arranged at the distal end of the tip element (10) A movable tip element (10) configured to be moved from an initial position in a displacement direction by displacement;
An active type position indicator having a force sensor for detecting a force acting on the tip (3), the force sensor acting on the tip element (10) against displacement of the tip An active position indicator comprising a resilient element and a transducer for converting the displacement of the tip of the tip element (10) into an electrical signal;
An active type position indicator, wherein the elastic element is a leaf spring (15, 21). 2. Active type according to claim 1, characterized in that due to the force of the leaf spring (15, 21) on the tip element (10), different forces acting on the tip element (10) are measured by a force sensor. Position indicator. The active type active position indicator according to claim 1 or 2, wherein the leaf spring (15, 21) is non-linear and has rigidity depending on the displacement of the tip. The active type position indicator according to any one of claims 1 to 3, wherein the rigidity of the leaf spring (15, 21) increases with an increasing displacement of the tip. The leaf springs (15, 21) are formed from one spring leaf material with at least one elastic spring leaf portion (15.1, 21.1) bent at a constant angle from the spring leaf surface; In the state where the normal of the spring plate surface of the spring plate material is perpendicular to the displacement direction and at least one elastic spring plate portion (15.1, 21.1) is elastic in the displacement direction, The active position indicator according to any one of claims 1 to 4, wherein a spring (15, 21) is arranged. The leaf spring (15) comprises a fixing element (15.3) made of a spring leaf material of the leaf spring (15) for securing the leaf spring (15). The active type position indicator as described in any one of -5. The leaf springs (15, 21) are provided with at least two elastic spring plate portions (15.1, 21.1), and these spring plate portions are elastic in the displacement direction and to the tip (3). The active type position indicator according to any one of claims 1 to 6, wherein the position indicator is acting against the force of the active position indicator. At least two resilient spring leaf portions (15.1, 21.1) are arranged to contact the tip element (10) for the first compression range of the leaf springs (21, 15) for small forces. The tip element (10) after the first compression range for the at least one first elastic spring plate portion (21.11) and the second compression range of the leaf springs (21, 15) for high force 8. An active position indicator according to claim 7, characterized in that it comprises at least one second elastic spring plate part (21.12) arranged to be in contact with. 9. The at least one second elastic spring plate portion (21.12) is more rigid than the at least one first elastic spring plate portion (21.11). An active type position indicator described in 1. The leaf spring (15) has a ring shape, and at this time, the central axis of the ring is parallel to the displacement direction, and at least one ring portion bent in the displacement direction is an elastic spring plate portion. (15.1) is formed, The active type position indicator as described in any one of Claims 7-9 characterized by the above-mentioned. At least one of the bending edges is in the direction of the outer circumferential side of the leaf spring (21) and the end of the elastic spring leaf portion (21.1) points to the center (C) of the leaf spring (21). The active position indicator according to any one of claims 7 to 9, characterized in that the elastic spring part (21.1) is bent. 12. At least two elastic spring plate portions (21.1) are cut from the spring plate material as triangular portions between the center (C) of the spring plate material and the bending edge. An active type position indicator described in 1. The force sensor includes a force detection mechanism housing (9.1), and a leaf spring (15, 21) is disposed in the force detection mechanism housing (9.1) between the housing wall and the tip element (10). Active position indicator according to any one of the preceding claims, characterized in that the tip element (10) is guided in the housing (9.1) of the force detection mechanism . The housing (9.1) of the force detection mechanism has the shape of a hollow cylinder with a tip element (10) in a state of moving along the cylinder axis. Active position indicator as described. A position signal circuit is provided, and the position signal circuit is connected to the movable tip element (10) via the leaf spring (15, 21) and is to be applied to the tip portion (3). The active type position indicator according to any one of claims 1 to 14, wherein the active type position indicator is configured to generate a position signal of the indicator, and the elastic element is conductive. The active position indicator according to any one of claims 1 to 15, wherein the transducer is a capacitive element having a capacitance value depending on the displacement of the tip. 17. The active position indicator according to claim 16, wherein the capacitive element has a capacitor distance depending on the displacement of the tip portion and a capacitor area depending on the displacement of the tip portion. A method for detecting a force on the tip (3) of an active position indicator, the method comprising the following steps: the tip of the tip (3) depending on the force applied to the tip (3) In a method comprising the step of detecting displacement,
A method wherein the leaf spring is used to act against the displacement of the tip caused by the force applied to the tip (3). An active position indicator according to any one of the preceding claims, wherein the touch system is configured to emit a position signal of a position indicator of the tip (3). Vessel (800, 5),
A touch system including a touch device configured to detect a position of a tip portion (3) of an active type position indicator based on a position signal transmitted from the position indicator.

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